csv in my example), and then click the Change program button. In the Set Associations dialog box, please click to select the extension of the specified file type (. Now you get into the Default Programs dialog box, please click the Associate a file type or protocol with a program option. Please open the Default Programs in Control Panel with opening a folder and pasting below path into the address box:Ĭontrol Panel\All Control Panel Items\Default ProgramsĢ. You can also associate the specified file type of Outlook attachments to a program in Control Panel to change the default programs of opening specific kind of Outlook attachments.ġ.